This concept is understood as the following energy difference: equation(1) NET=(SWd+LWd)−(SWu+LWu).NET=(SWd+LWd)−(SWu+LWu).This
is the difference between the total radiant energy flux arriving from the atmosphere at the sea surface (SWd + LWd), and the total radiant energy flux emitted from the sea surface into the atmosphere (SWU + LWU). SWd is the downward solar (short-wave) radiation flux and LWd is the downward thermal (long-wave) radiation flux of the atmosphere. In contrast, the upward radiation flux (SWU + LWU) is the sum of short- wave solar radiation flux SWU reflected Selleckchem PD0332991 upwards from the sea surface (this includes radiation emerging from the sea as a result of backscattering Anti-diabetic Compound Library price within the water) and the long-wave thermal radiation flux emitted by the sea surface LWu. Figure 7 (maps b–f) shows the resultant irradiance of the sea surface NET radiation flux and its corresponding downward and upward components (short-wave – SWd, SWu; long-wave – LWd, LWu). For comparison, the map in Figure 7a shows the distribution of the sea surface temperature SST, which bears a strong influence on the NET radiation flux, and is the principal input datum for calculating the radiation balance at the sea surface. The distributions of values on these maps were
calculated using the algorithms described in Krężel et al. (2008), Zapadka et al. (2008), Woźniak and Krężel (2010) and METEO-FRANCE (2010). The input data for these algorithms were the SEVIRI (MSG) radiometer measurements and data from the prognostic
UM weather model. In the case shown in Figure 7, which refers to the situation in the late morning (11:00 UTC on 24 April 2011), the values of the NET radiation flux are positive over the entire Baltic Sea. Nonetheless, this resultant NET radiation flux can also take instantaneous negative values. During the daytime the values of this flux are usually positive, because the downward solar radiation flux SWd is positive. At night, however, the NET radiation flux is normally negative, because the long-wave upward radiation flux LWu, associated with SST, is greater ID-8 than the long-wave downward radiation flux LWd. As already stated in the Introduction, the DESAMBEM algorithm also makes it possible to estimate indirectly, on the basis of satellite data, a numerous set of spatial distributions of various parameters characterizing the optical conditions for marine photosynthesis, such as the depth of the euphotic zone and the photosynthetic index of the waters, as well as the parameters determining the physiological state (including the condition) of the natural plant communities occurring there. These parameters include the maximum possible assimilation number, the maximum quantum efficiency of photosynthesis and the so-called non-photosynthetic pigment factor.